Chert (Honey Chert or Chalcedony Pebble)
Cryptocrystalline Quartz (SiO2)
Category
Browse sedimentary (if natural jasper) or artificial (if slag) specimens identified by the Rock Identifier community.
Chert (Honey Chert or Chalcedony Pebble)
Cryptocrystalline Quartz (SiO2)
Chrysocolla
Chrysocolla; (Cu,Al)2H2Si2O5(OH)4·nH2O
Tiger's Eye
Tiger's Eye (Pseudomorph of Quartz after Crocidolite), SiO2
Quartz / Common Agate
Silicon Dioxide (SiO2)
Fossiliferous Limestone with Rugose Coral
Calcium Carbonate (CaCO3) featuring Rugosa (extinct order of solitary and colony corals)
Greywacke (River Slikkenstone)
Greywacke (Impure Sandstone)
Agate (specifically Carnelian Agate or Lake Superior style Agate)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Botryoidal Quartz / Calcite Geode crust
Silicon Dioxide (SiO2) or Calcium Carbonate (CaCO3)
Rough Corundum (likely Sapphire or Common Corundum)
Aluminum oxide (Al2O3)
Limestone
Calcium Carbonate (CaCO3)
Quartz Geode
Crystalline Silicon Dioxide (SiO2) in a Geodic structure
Geode with Quartz and Chalcedony
Silicon Dioxide (SiO2)
Amber Flint (Chert)
Cryptocrystalline Quartz (Silicon Dioxide, SiO2)
Desert Varnish (on Sandstone)
Rock Varnish (composed of Manganese oxides, Iron oxides, and Clay minerals)
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Fossiliferous Limestone (Coquina / Shell Limestone)
Bioclastic Limestone (CaCO3)
Quartzite
Quartzite (predominantly SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Banded Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Sandstone Concretion with Quartz Center
Sedimentary Clastic Rock (SiO2 matrix with Quartz core)
Schist (Micaceous Schist)
Schist (comprising Muscovite/Biotite mica, Quartz, and Feldspar)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions (Hematite/Goethite)
Chert Geode or Nodule
Microcrystalline Quartz (SiO2)
Banded Agate (River Stone)
Agate (Silicon Dioxide - SiO2)
Gastly (Trick or Trade Halloween Series)
Cellulose-carbonaceous composite (Lignocellulose laminated with pigmentary polymers)
Quartzite (River Pebble)
Quartzite (Mainly SiO2)
River Cobble (likely Quartzite)
Metamorphosed Sandstone (SiO2)
Chert (specifically Flint or Common Chert)
Microcrystalline Quartz (SiO2)
Chert (Flint Nobule)
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trivalent iron (Fe3+) impurities
Petrified Wood
Silicified wood (Quartz/Chalcedony - SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Quartzite
Quartzite (primarily composed of SiO O₂)
Basalt
Basalt (Mafic Extrusive)
Quartzite / Sandstone / Chert Mix
Silicon Dioxide (SiO2)
Fossilized Coral (Honeycomb Coral)
Favosites (extinct genus of tabulate corals), CaCO3 (Calcium Carbonate)
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
River Pebbles (Stream-rounded rocks)
Fluvial Detritus (varied mineralogy)
Basalt River Stone
Basalt (Aphanitic Mafic Igneous Rock)
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
Chert (Brecciated Chert)
Silicon Dioxide (SiO2)